Clothes dryer with reversible blower



Nov. 29, 1960 Filed Sept. 26, 1958 v P, G. HUGHES CLOTHES DRYER WITHREVERSIBLE BLOWER 4 Sheets-Sheet l INVENTOR.

PHIL! P e. HUGHES wwamw HIS ATTORNEY Nov. 29, 1960 P. G. HUGHES CLOTHESDRYER WITH REVERSIBLE BLowER 4 Sheets-Sheet 2 Filed Sept. 26, 1958IUUUUUUUU INVHVTOR.

PHILIP G. HUGHES HIS ATTORNEY Nov. 29, 1960 Filed Sept 26, 1958 P.' G.HUGHES 2,961,776

CLOTHES DRYER WITH REVERSIBLE BLOWER 4 Sheets-Sheet 3 INVENTOR.

PHILIP G. HUGHES HIS ATTORNEY Nov. 29, 1960 P. G. HUGHES CLOTHES DRYERwzrm REVERSIBLE BLOWER 4 Sheets-Sheet 4 Filed Sept. 26, 1958 INVENTOR-PHILIP 6. HUGHES Has A'rroansv United 3 States Patent Of CLOTHES DRYERWITH REVERSIBLE BLOWER Philip G. Hughes, Anchorage, Ky., assignor toGeneral Electric Company, a corporation of New York Filed Sept. 26,1958, so. No. 763,670

6 Claims. (Cl. 34-133 This invention relates to clothes dryers, and moreparticularly to dryers of the type which incorporate an air blower formoving heated air over the clothes to effect moisture removal therefrom.

Heretofore, the pumping rate provided by the blower in a dryer has beensubstantially constant. This has resulted primarily from manufacturingand economic considerations.* One such economic factor is, for instance,the fact that the same electric motor is generally used to drive theblower and to rotate the basket, and therefore any variability in theblower rotational speed to improve the dryer performance would also,unless clutching means were used, involve a change in the basketrotational speed. Since the'rotational speed of the basket is criticalinsofar as obtaining a proper tumbling pattern of the clothes thereinisv concerned, variations in the basket speed are obviously out of thequestion. For these and other related reasons, domestic dryers have todate provided a single speedbl'ower. I

Despite the fact that single speed blowers are the rule, substantialadvantages to be obtained from a two speed blower have occurred to me.For instance, a limited air flow optimum for drying purposes could beprovided during the heating operation, and then, during the cool-downperiod which is often provided in domestic clothes dryers at the end. ofthe heating operation tocool the clothes down to a point where theoperator can handle them readily, a higher air flow could then beprovided toprovide a more effective cooling of the clothes. Anotherfactor I havenoted is that for different types of cycles different airflows may be desirable.

In view of the foregoing, it is an object of this invention to provide anew and improved arrangement capable of giving two different air flowsin a domestic clothes dryer.

A further object of the invention is to achieve a twoair-fiow blower bymaking the blower reversible, with the output of the blower passing inthe same direction for both directions of rotation but being differentin amount ,for each rotational direction.

A further object of the invention is to achieve a reversible blower bymaking the motor which powers both the blower and the clothes tumblingbasket reversible so that the basket and blower may be rotated in eitherdirection at the same speed, with different airfiows being provided forthe two directions of rotation.

In carrying out the invention in one form thereof, I provide a clothesdrying machine which has the conventional rotatable clothes basketdriven by suitable means at a predetermined speed so as to tumble theclothes therein. Inlet and outlet air conduits lead respectively .to andfrom the basket and a heater is positioned in the inlet conduit so as toheat the air before it reaches the basket; thus, when the air passesover the clothes in the basket it effects moisture removal therefrom. Tocause the air to flow through the basket from the inlet heater 1 providea rotatable blower which, for any given speed,

a different flow rate when driven in the other direction.

Patented Nov. 29,1960

ice 3 To take advantage of this characteristic of the blower, I providesuitable means for operating the blower in either direction, and forselecting the direction of blower rotation so as to make advantageoususe thereof during the drying cycle.

The subject matter which I regard as my invention is particularlypointed out and distinctly claimed in the concluding portion of thisspecification. My invention however, both as to organization and methodof operation together with further objects and advantages thereof, maybest be understood by reference to the following description taken inconjunction with the accompanying drawmgs.

In the drawings, Fig. 1 is a side elevational view of a clothes dryerembodying my invention, the view being partially broken away andpartially sectionalized to illustrate details of the dryer;

' Fig. 2 is a horizontal sectional view of the dryer with the basketremoved and with certain surfaces broken away and partly sectionalizedto illustrate further details;

Fig. 3 is an enlarged fragmentary view in perspective of a blowermechanism suitable for use in connection with my improved construction;

Fig. 4 is a diagram showing an improved dryer control circuitincorporating my invention; and

Fig. 5 is a diagram showing a second improved dryer control circuitarrangement incorporating my invention.

Referring now to Figs. 1 and 2 of the drawings, I have shown therein adomestic clothes dryer 1 which includes a rotatable open-ended clothestumbling basket 2 mounted a within a suitable cabinet 3 which enclosesin on all sides.

provides one flow rate when driven in one direction and 'The basket ismounted for rotation about a horizontal axis and comprises a cylindricaldrum-like member having an outer cylindrical wall 4 and front and rearwalls 5 and 6. The outer cylindrical wall 4 of the basket is imperforateover its entire length, and on its interior surface is preferablyprovided with a plurality of clothes tumbling ribs such as illustratedat 7. Basket 2 is rotatably supported within the outer cabinet 3 bymeans of a plurality of roller wheels 8, 9, 10 and 11 (see Fig. 2).Wheels 8 and 9 are mounted on an idler shaft 12 and wheels 10 and 11 aremounted on a drive shaft 13. Shaft 12 has no driving connection; shaft13 is driven from the drive motor 14 of the dryer through a suitabletransmission such as belt and pulley drive 15. As will be set forth indetail, motor 14 is preferably of the reversible type, operable at thesame speed in both directions,

As shown, both the idler shaft 12 and the drive shaft 13 are supportedadjacent the front and the rear of cabinet 3 by means of suitablebearings mounted in front and rear support plates 16 and 17. Beingfreely supported on the roller wheels, basket 2 will turn thereonwhenever drive shaft 13 is turned by motor 14, the frictional engagementbetween the side Wall of the basket and rollers 10 and 11 causing thebasket to turn as the shaft turns. The ratio of the driving and drivenpulleys in the drive 15 is suitably chosen so that the basket is rotatedat an appropriate speed to provide a tumbling action for articles ofclothes placed therein.

In order that a stream of drying air may be introduced and passedthrough the clothes basket, the basket is apera tured at both front andrear ends. Specifically, a central aperture 18 is provided in wall 5 anda similar aperture 19 is provided in wall 6. Rear opening 19 issubstantially covered or closed by means of. a stationary bulkhead. 20which is mounted within the dryer cabinet by means of a pair of crossbraces 21 and 22. As shown, a suitable clearance is provided between theedge of aperture19 and the outer flange23 of bulkhead 20 so that thereis nocou-Q tact between the basket and the bulkhead during rotation ofthe basket. The front opening 18 of the basket is likewise substantiallyclosed by means of a stationary bulk head, generally indicated at 24.

Bulkhead 24 is made up of a number of adjacent members including theinner surface 25 of an access door 26 mounted on cabinet 3, seat 27 ofthe door, the inner surface 29 of an exhaust duct 30 leading from thebasket, and an annular flange 31 mounted on seat 27 and the duct wall.All of these members cooperate to'define a generally circular bulkheadcovering opening 18, with flange 31 at its outer edge surrounding theopening. As with the rear bulkhead, a suitable clearance is provided sothat there is no rubbing between the edge of opening 18 and the edge ofbulkhead 24 during rotation of the clothes basket.

Door 26 includes an outer flat section 32 and an inwardly extendinghollow section 33 mounted on the flat section. Hollow section 33 extendsinto the door seat 27 when the door is closed, and the door surface 25which comprises part of bulkhead 24 is actually the inner wall of thishollow section.

In the illustrated dryer, the drying air flow is introduced into thebasket by means of a screened air inlet 34 in the rear bulkhead 20; theflow then passes through the basket, and out through a screened opening35 formed in wall 25 of the door section 33. The air movement iseffected by a blower 36, of the radial type having air moving vanes 37(Fig. 3), which is secured to a motor shaft extension 37a of motor 14 soas to be driven thereby. The air then flows through an opening 38 indoor 26 which is aligned with an opening 39 in door seat 27 leading toduct 30 and blower 36 when the door is closed. It can be seen that wall25 of door section 33 is in effect a shield to prevent the clothes fromplugging opening 39 which may, as shown in Fig. 2, be provided with agrill 40 to prevent clothes from falling into duct 30 during loading andunloading of the dryer. The blower then exhausts the air from themachine through the outlet duct 41 which extends from the blower to anopening (not shown) provided in the rear of cabinet 3. It can be seenthat ducts 30 and 41 form together an outlet conduit for the air flowingout of the'basket.

A suitable lint filter 42 may be positioned in any convenient location,such as in duct 30 as shown, to perform the usual function of removinglint picked up by the air in the clothes basket.

The air drawn through the above-described duct system by blower 36 ispulled into the basket 2 through opening 34 from an intake duct orconduit 43 which is mounted on the rear bulkhead 20 and which is open atits lower end 44 within cabinet 3. Thus, when blower 36 operates, air isdrawn into the cabinet through any suitable opening (not shown) providedtherein for that purpose, and then flows to the inlet 44 of duct 43,through the duct 43, and over a suitable heater 45 through opening 34into basket 2. The air flow then passes out through opening 35, the doorsection 33, duct 30, blower 36, and duct 41 to the aforementionedexhaust opening. To prevent any leakage into the basket during thisoperation, suitable air seals 46 and 47 are provided to prevent leakagethrough openings 18 and 19 respectively. Seals 46 and 47 are preferablyformed of felt-like material, and are biased against the basket so thatin addition to serving as seals they also serve as thrust bearings tomaintain the basket in its proper position on rollers 8, 9, and 11. Thisconstruction is fully described and claimed in Patent 2,835,048, issuedon May 20, 1958 to Eugene G. Olthuis, and assigned to General ElectricCompany, the assignee of the present invention.

Referring particularly to Fig. 3, it will be seen that the vanes 37 ofblower 36 are curved in configuration; in effect this providesrelatively high efliciency of the blower for rotation in the directionindicated by arrow A and relatively low efiiciency when the blower isrotating in the direction of arrow B. Also, of course, the blowerhousing a scroll shaped, as shown at 47a, in the conventional manner soas to improve the air flow during rotation in direction A and decreasethe air. flow during rotation in 4 direction B. In other words, theblower provides a high air flow when rotated in direction A and a lowair flow when rotated in direction B.

Referring now to Fig. 4, there is shown a circuit making use of the dualflow rate characteristic of blower 36, wherein the different flow ratesare provided in connection with different steps of the drying cycle inorder to provide the most effective cooperation between the heatingelement 45 and the blower 36. The system of Fig. 4 is energized from athree wire power supply (not shown) through supply conductors 48 and 49and the neutral wire 50. For domestic use the conductors 48 and 49 arenormally connected across 230 volts, with 115 volts appearing betweenthe neutral line 50 and each of the supply conductors 48 and 49.

The main components of the system energized through wires 48, 49 and 50are the heating element 45, the motor 14, and a timing control motor 51which, through an appropriate gear train 52, operates cams 53, 54 and55. The initial position of cams 53, 54 and 55 is presettable by meansof a dial 56 which is positioned on a control panel 57 (Fig. 1) normallyprovided at the top of the machine. At the start of the drying cycle thedial 56 is rotated until cam 53 causes a pair of movable contacts 58 and59 of a switch generally indicated at 60 to engage stationary contacts61 and 62 of the switch. The switch also includes a third stationarycontact 63 for a purpose which will appear more clearly herebelow. Withthe dial in this starting position, cam 54 is in a position which forcestogether contacts 64 and 65 of a switch 66, and cam 55 closes all threecontacts 67, 68 and 69 of a switch 70.

With the switches in this position, an energizing circuit for timer 51is completed, starting at conductor 48, through conductor 71, contacts64 and 65 of switch 66, conductor 72, motor 51, and conductors 73 and 74back to neutral line 50.

An energizing circuit for the motor 14 is also completed; starting withconductor 48, the circuit for motor 14 extends through conductor 75,contacts 68 and 67 of switch 70, and a conductor 76 to a pair ofparallel conductors 77 and 78. From conductor 78, the circuit for therunning winding of the motor is completed through the running winding 79and conductor 80 back to neutral wire 50. A parallel circuit for thestart winding 81 of the motor is provided from conductor 77 throughcontacts 58 and 61 of switch 60, conductor 82, and bridging contact 33of the motor centrifugal mechanism 84, to winding 81; from the winding,the circuit is completed through conductor 85, contacts 62 and 59 ofswitch 60, and conductor 74 back to neutral wire 50. With both runningwinding 79 and starting winding 81 thus energized, motor 14 will startto rotate in a predetermined direction. The direction of this rotationis selected to be effective to rotate the blower 36 of Fig. 3 in thedirection of arrow B, that is, with the smaller of the two possible airflows.

When the motor comes up to speed, the centrifugal mechanism 84 opens thecircuit of start winding 81 by movement of bridging contact 83. Also atthis time, the heater 45 becomes energized because bridging contact 87moves into position to connect conductors 88 and 49. This then providesfor completion of a heating circuit, starting with conductor 48, throughconductor 75, contacts 69 and 68 of switch 70, conductor 89, the heatingelement 45, a suitable temperature limiting bimetallic disk 90,conductor 88, contact 87 and conductor 49. Thus, with dial 56 set asdescribed to provide heating for a predetermined time, the timer motorwill be energized to control the operation, the drive motor will beenergized to effect rotation of drum 2 and rotation of blower 36 indirection B, and the heating element will be energized except asotherwise controlled by disk 90.

In accordance with one conventional type of drying cycle, I provide aperiod of several minutes at the end of the drying cycle when the heater45 is shut off but tumbling of the clothes and flow of air over theclothes is de-energization of the heating element 45 is effected whenmotor 51 moves cam 55 to a position where contacts 67,

68 and 69 separate. At the same time that the circuit to the heatingelement 45 is opened, the action of the switch 70 opens the circuit tomotor 14. Cam 53 then causes switch 60 to be moved so that contact 58engages contact 62 and contact 59 engages contact 63. This causesreversal of the connections of starting winding 81 with respect torunning winding 79; therefore, since the motor has stopped and bridgingcontact 83 enables the circuit to be completed to starting winding 81upon a reclosing of contacts 67 and 68 by cam 55, the motor 14 will beenergized in the opposite direction to that in which it was drivenduring the heating operation. It will be noted that cam 55 at this timecloses only contacts 67 and 68. Contact 69 is left disconnected so thatno 'energization of element 45 can take place.

With the motor 14 now rotating in the opposite direction, the drive 15provides the same speed of rotation of the drive wheels 10 and 11 in theopposite direction, i.e., basket 2 will rotate at the same speed asbefore but in the opposite direction. Since the speed is the criticalelement for the basket, the same appropriate tumbling pattern will beprovided for the clothes.

At this time, with the opposite direction of rotation of motor 14,blower 36 is being driven in the, direction A so as to provide asubstantially higher air flow than before. Thus, in combination with thecessation of heating, a substantially higher flow of air is being passedover the clothes during the cool-down period. This aids to a verysubstantial extent in the cooling effect on the clothes, thus making theclothes much more agreeable for the operator to handle While nonethelesspermitting the optimum combination of air flow and heat to be obtainedduring the heating operation. After an appropriate cooldown period,which may be on the order of nine minutes, for instance, the timer motor51 will have run to the point where contacts 67 and 68 are opened andcontacts 64 and 65 of switch 66 are opened; this de-energizes all partsof the dryer and terminates the cycle.

It will thus be observed that the invention utilizes the characteristicsof blower 36 by which it provides dif =fering air flows with differentdirections of rotation to effect the optimum air flow for the heatingoperation and the optimum air flow for the cooling operation.

Referring now to Fig. of the drawings there will be described a secondcontrol circuit utilizing my improved blower arrangement, with likenumerals being used for parts identical to those in Fig. 4. The onedifierence between the arrangements of Figs. 4 and 5 is that instead ofthe switch 60 being controlled by a motor-operated cam 53, as in thearrangement of Fig. 4, switch 60 in the arrangement of Fig. 5 iscontrolled by manually operable pushbuttons 91 and 92. Depression ofbutton 91 moves member 93 which acts through a toggle spring 94 to movecontacts 58 and 59 into engagement with contacts 61 and 62. In the samemanner, manual depression of button 92 acts through a link 95 to causetoggle 94 to move contacts 58 and 59 into engagement with contacts 62and 63.

It will be seen that, with this arrangement, the motor reversing switch60 is removed from control by timer 51 and is placed under manualcontrol. This is particularly advantageous, for instance, where agreater or lesser heating effect is desired with a single wattage inputfrom the heater. This occurs, for instance, where, during the drying ofwash and wear fabrics which need to be de- Wrinkled, the temperatureshould reach a higher level and the air flow should therefore be lowerthan the normal optimum air how for drying of synthetics. In otherwords, for the tie-wrinkle cycle the operator would push down member 92to select the rotational direction of operation of blower 36 whichprovides the low air flow;

for a regular drying cycle, member 91 is pushed in to select therotational direction which provide the higher air flow.

A further advantageous use of the reversible blower of this inventioncan be made where dryers are manufactured for use on either volts or 230volts. To improve the drying efiect in machines connected to be operatedat 115 volts, the rotational direction may be selected to provide thelower air flow; in machines to be operated on 230 volts, the reverserotational direction would be selected to provide the higher air flow.Thus, dryers to be used on the different voltages could be manufacturedalike withoutsacrificing optimum performance in either.

It will be seen from the foregoing that my invention provides animproved dryer arrangement whereby two different air flows can beobtained from the same blower at the same rotational velocity byreversal of the direction of rotation of the blower. It will further beseen that by so doing the blower can still be operated by the same motorwhich rotates the drum, without any additional clutching being necessarysince the drum will rotate at the proper speed in either direction andthe clothes will thus have their proper tumbling pattern regardless ofthe direction of rotation.

While in accordance with the patent statutes I have described what atpresent is considered to be the preferred embodiment of my invention, itwill be obvious to those skilled in the art that various changes andmodifications may be made therein without departing from the invention,and it is, therefore, aimed in the appended claims to cover all suchequivalent variations as fall within the true spirit and scope of theinvention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. -In a clothes drying machine, a rotatable clothes basket, inlet andoutlet air conduits leading respectively to and from said basket, aheater in said inlet conduit, control means for operating said heater atat least part of the time during a drying cycle, a rotatable blowerarranged in one of said conduits to provide a predetermined air flowrate over said heater and through said basket upon rotation of saidblower at a predetermined speed in one direction and to provide a seconddifferent predetermined air flow rate over said heater and through saidbasket upon rotation of said blower at said predetermined speed in theopposite direction, means for operating said blower in either direction,and control means for selecting the direction of blower rotation therebyto select one of the two different air flow rates.

2. In a clothes drying machine, a rotatable clothes basket, inlet andoutlet air conduits leading respectively to and from said basket, aheater in said inlet conduit, control means for operating said heater atat least part of the time during a drying cycle, a rotatable blowerarranged in one or said conduits to provide a predetermined air flowrate over said heater and through said basket upon rotation in onedirection at a predetermined speed and to provide a second differentpredetermined air flow rate over said heater and through said basketupon rotation at said predetermined speed in the other direction, areversible motor, means connecting said hasket to said motor to efiectrotation of said basket, means connecting said blower to said motor toeffect rotation of said blower, said motor means rotating said basket ineither direction at a predetermined speed for tumbling clothes therein,and control means for selecting the direction of motor rotation toprovide alternatively one of said two predetermined air flow rates.

3. In a clothes drying machine, a rotatable clothes basket, inlet andoutlet air conduits leading respectively to and from said basket, aheater in said inlet conduit, a rotatable blower arranged in one of saidconduits to provide a first predetermined air flow rate over said heaterand through said basket upon rotation at a predetermined speed in onedirection and to provide a sec ond diiferent predetermined air flow rateover said heater and through said basket upon rotation at the predetermined speed in the opposite direction, means for operating said blowerin either direction, means controlling operation of said heater andcontrolling the direction of operation of said blower, said controlmeans providing for operation of said heater simultaneously withoperation of said blower in the direction to give the lower of saidpredetermined air flow rates, said control means then shutting off saidheater and providing operation of said blower in the other of saiddirections to provide the higher rate of said air flow, said controlmeans thereafter shutting off said blower operating means.

4. The apparatus defined in claim 1 wherein'said selecting control meansare manually operable to provide the operator with his selection as 'towhether the air flow will be at a high rate or at a low 'rate during aparticular drying operation thereby to provide two different heatingeffects in said basket.

5. In a clothes drying machine, a rotatable clothes'basket, inlet andoutlet air conduits leading respectively to and from said basket, aheater in said inlet conduit, an air blower arranged in one of saidconduits to provide a first predetermined air flow rate over said heaterand through said basket upon rotation at a predetermined speed in onedirection and to provide a second different predetermined air flow rateover said heater and through said basket upon rotation at saidpredetermined speed in the opposite direction, common reversible drivemeans connected'to reversibly rotate said basket and connected toreversibly operate said blower comprising a reversible electric motor,and means for selecting the direction of motor rotation.

6. The apparatus defined in claim 5 wherein said motor comprises twosingle phase windings connected in parallel, said means for selectingthe direction of blower rotation comprising switch means for reversingthe polarity of one of said windings relative to the other.

References Cited in the file of this patent UNITED STATES PATENTS OrrAug. 11, 1936 McMahan July 1, 1941 Morgan et a1. Nov. 30, 1943 ManeckeOct. 13, 1953

